If you thought your poinsettia was doomed to certain death once the holidays were over, it's time to rethink how you treat your poinsettia. Not only are these colorful plants a symbol of holiday cheer, they are hardy enough to keep alive from year to year, growing larger and bushier than you ever thought possible. With proper care, your poinsettia can brighten your holidays for years and can be an attractive houseplant during the summer months.
Place poinsettias on a sunny windowsill once the colored bracts fade in mid-winter. Some foliage may yellow and drop. Remove any discolored or faded leaves and water when the soil dries.
Pinch out the center leaves on branches when growth resumes in the spring. This forces new branches to sprout from the main stalk and creates dense, compact foliage. Each new branch will produce "blooms" the next season.
Repot the poinsettia in a pot that is 2 to 4 inches larger than the original. Use a lightweight soil mixture that drains easily and provides aeration for young roots. Mix one part potting soil, two parts peat moss and one part perlite or vermiculite to make your own mixture. Add one teaspoon of bone meal per 2½ cups of soil mixture.
Water thoroughly until water runs free from the drainage holes at the bottom of the pot. Place the pot outside in a shady location once the danger of frost has passed and nighttime temperatures remain above 60 degrees F.
Move the plant to sunny location by gradually increasing exposure to full sun. Sink the pot in the soil in the garden bed, if preferred. Turn the pot each week to prevent roots from growing through the drainage holes and into the soil.
Fertilize with a balanced fertilizer like 10-10-10 once new growth is 1 inch long. Repeat at seven to 10 intervals until September.
Pinch or trim back new growth when it is 4 to 6 inches long. Repeat pinching once every four to six weeks.
Move poinsettias inside in late summer to prepare for winter blooms.
Place the poinsettia in a dark room for 14 hours a day beginning in early October to force blooms for the December holidays. Poinsettias will not rebloom without complete darkness for at least 14 hours day.
Cover with a cardboard box or place in a closet if you do not have a room that is in total darkness for 14 hours. According to the University of Rhode Island horticulture program, even stray light from outside sources may inhibit blooming.
Move to the desired location once leaf color has developed, typically by the first or second week in December.